Hypertension is one of the most common cardiovascular diseases, and is closely related to some of the most fatal human diseases, such as coronary heart disease, cerebrovascular diseases, etc. Although the incidence of hypertension in China is not as high as that in Western countries, it increases year by year. With the improvement of living standards and the degradation of the environment, the number of patients suffered from cardiovascular diseases such as hypertension, hyperlipemia and hypercholesterolemia keeps increasing. According to the report, the number of hypertension patients in China has reached 150 million by the end of 2003, and increases at a rate of 5 million per year. Great attention has been paid all over the world to the researches on hypertension, ranging from pathogenesis to clinical prevention and treatment of the disease. Hypertension mainly impairs the blood vessels of humans, rendering arterial angiosclerosis and arteriarctia, which are generally called “arteriosclerosis”. When hypertension is combined with diabetes mellitus, the damage to blood vessels would become accelerated and more severe, and the conditions of patients would be worsened rapidly, to which active treatment should be applied.
Amlodipine is a calcium channel blocker that prevents calcium from transmembranely entering myocardial cells and vascular smooth muscle cells, and thus has anti-hypertension effect. Amlodipine exists as two isoforms, levo-amlodipine and dextro-amlodipine, wherein the activity of levo-amlodipine is 1000 times as high as that of the dextroisomer, and twice as high as that of the racemate. Amlodipine exhibits higher selectivity on vascular smooth muscle than that of nifedipine, and can increase cardiac output and coronary flow of the patients suffered from myocardial ischemia, increase myocardial oxygen supply and decrease oxygen consumption, and improve locomotive ability. Additionally, amlodipine may also activate LDL receptor, reduce the accumulation of fat in artery wall, inhibit the synthesis of collagens, and thus has anti-arteriosclerosis effects. The anti-hypertension effect of amlodipine is based on the mechanism of direct relaxation of the vascular smooth muscle. Although the exact angina-relieving mechanism thereof has not been ascertained, amlodipine can expand peripheral arteriola and coronary artery, reduce peripheral resistance, release coronary artery spasm, decrease cardiac after-load, reduce cardiac energy consumption and oxygen requirement, and thus relieve angina.
Rosuvastatin calcium is a synthesized statin drug which was developed by Shionogi Co., Ltd. (Shionogi Company, Osaka) and assigned to AstraZeneca UK Limited in April, 1998. Rosuvastatin is a selective 3-hydroxyl-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, and may be used in the treatment of atheroma, hyperlipemia, familial hypercholesterolemia and similar diseases. The molecular formula of rosuvastatin calcium is shown as follows:

In view of the clinically testing results and the comparison data among statins, rosuvastatin calcium is indeed a “super statin”, which has extremely good antilipemic effects, and is so far the most potent antilipemic drug.
Chinese Patent Application CN200510094723.3 discloses a pharmaceutical composition comprising 5-40 wt. % of amlodipine besylate and 5-40 wt. % of rosuvastatin calcium, and a method for preparing the same.
Chinese Patent Application CN200610028434.8 discloses a pharmaceutical composition comprising a therapeutically effective amount of amlodipine and a therapeutically effective amount of rosuvastatin calcium, and a method for preparing the same.
Although the combination of amlodipine and rosuvastatin could bring both antihypertensive and antilipemic effects as described in the above two patent applications, these effects are not sufficient for hypertensive patients who may have high risk of cardiovascular diseases, as chronic hypertension may result in damages to key organs such as cardiovascular system and kidney. Accordingly, the objective of antihypertensive treatment is not only to reduce the blood pressure to desired level, but also to rectify the coexisting risk factors such as cardiovascular diseases. Meanwhile, a suitable medicament shall be selected to improve metabolic disorders and prognosis of the patients. Therefore, it is desired in clinical treatment to find a multidrug combination therapy which could treat hypertensive diseases, while effectively controlling the incidence of associated cardiovascular diseases, and more potently improving the survival and prognosis of hypertensive patients.